Jan 16, 2009

Lifestyle - Oral contraceptives carry risks

WASHINGTON: Although 80 percent women in the US have used oral contraceptives at one time or another since the sixties, these could carry unknown long-term risks.More so when women's lifestyles change and new forms of contraceptives become available, according to specialists in women's heart disease at Cedars-Sinai Medical Centre(C-SMC).

"As women use these therapies more frequently and for longer periods of time, there is an urgent need to better understand and minimise associated cardiovascular risks," said C. Noel Bairey Merz, director of the Women's Heart Center(WHC)at the C-SMC.

Women at high risk for cardiovascular problems, especially those who smoke, should consider alternative forms of contraception.Those with other cardiac risk factors, such as hypertension or elevated cholesterol, can consider using hormonal contraceptives if they are carefully monitored by their health care provider, said Bairey Merz, who is also professor of medicine at Cedars-Sinai.

Any woman considering the use of contraceptives should be evaluated for cholesterol levels, blood pressure, smoking, diabetes, kidney problems, obesity and other vascular diseases, including migraines.

Healthy, non-smoking women who are 35 or older can continue taking a low dose oral contraceptive until 50 to 55 years after reviewing the risks and benefits. Bairey Merz co-authored the study that provides an overview of the known cardiovascular risks and benefits of hormonal contraceptives while pointing out areas that require further research.

Reproductive hormones affect the tone and function of blood vessels as well as lipid (fat) levels in the blood. Low oestrogen levels have been found to increase risk of coronary atherosclerosis (thickening and hardening of artery walls) and "adverse cardiac events", such as heart attacks and strokes.

But the use of supplemental oestrogen in hormone replacement therapy has been linked to an elevated risk of blood clots that can lead to heart attacks and strokes. "Health care providers must evaluate each woman's risk factors, especially those related to cardiovascular health, prior to starting any contraceptive therapy," she said.

"Although pre-menopausal women have a much lower risk of cardiovascular disease, routine screening for potential problems and follow-up is important," said Chrisandra L. Shufelt, assistant director of the WHC and co-author of the study.

The earlier contraceptives used higher levels of oestrogen than the newer formulations, which are now available not only in pill form but in patches and vaginal rings. Newer formulations use lower doses of oestrogen, safer in terms of lowering the risk of blood clots, and they tend to use a progestin, a synthetic version of progesterone that may slightly reduce blood pressure, said Bairey Merz, according to a Cedars-Sinai release.

Since 2000, death rates have increased in women between the ages of 35 and 44, while all other age groups have seen a decline. These findings are slated for publication in the Jan 20 issue of the Journal of the American College of Cardiology.